Mobile sea platform



July 17, 1962 R. G. LE TOURNEAU MOBILE SEA PLATFORM Filed July 22, 19575 Sheets-Sheet 1 Fig. 1

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differ/25y United States Patent" 3,044,269 MOBILE SEA PLATFORM Robert G.Le Tourneau, P.O. Box 2307, Lougview, Tex. Filed July 22, 1957, Ser. No.673,491 5 Claims. (Cl. 6146.5)

My invention relates generally to improvements in mobile sea platforms,and particularly to floatable vessels which are convertible intostabilized structures over bodies of water. My invention is especiallyapplicable to offshore or tidelands oil exploration, drilling, andproducing operations.

This application includes disclosure of certain improvements over themobile sea platforms of my co-pending applications, S.N. 473,885,nowabandoned, filed December 8, 1954, and SN. 625,710, filed December 3,1956, now U.S. Patent No. 2,924,077.

The general object of my invention is to provide an improved mobile seaplatform.

Another object of my invention is to provide a mobile sea platformhaving improved hull structure.

Another object of my invention is to provide a mobile sea platformincorporating improved spud tower structure.

Another object of my invention is to provide improved rack structure foruse in the hull elevating system of a mobile sea platform.

Another object of my invention is to provide improved rack and rackguide structure for use in the hull elevat-' ing system of a mobile seaplatform.

- Another object of my invention is to provide improved rack drivearrangements for use in the hull elevating system of a mobile seaplatform.

These and other objects are effected by my invention as will be apparentfrom the following description taken in accordance with the accompanyingdrawings, forming FIG. 6 is a section view .taken at line 66 of FIG. 2;

; FIG. 7 is a section view taken at line 77 of 'FIG. -2,

with rack guide structures omitted;

FIG. 8 is a schematic side elevational view, partly in phantom, showinga rack drive assembly;

FIG. 9 is a schematic view, partly'in section, taken along line 9-9 of'FIG. 8, plus a showing of portions of a spud well and hull structure;

on line 10-10 of FIG. 2; and

FIG. 11 is a detail schematic transverse section view of a spud towercolumn.

Turning now to. the drawings, the basic structure of the platform isshown by FIGS. 1, 2, 6 and 7. The hull 11 has the general shape of anisosceles triangle in plan, with a spud well located at each corner ofthe triangle, as shown by FIG. 2. The spud well at the triangle vertexwill be referred to herein as the forward spud well 13, and the otherswill be referred to as the rightand left rear spud wells 15, 17,respectively. The principal parts of the hull are sidewalls, bottom,upper or main deck, lower or inner deck, upper deck support beams, upperdeck support columns, and lower deck support bulkheads. The hull sidewall structure comprises upper and lower box beams 19, 21 held invertically aligned rigid spaced parallel relation by formed steel platewall members 23, these steel FIG. 10 is a schematic perspective sectionview taken 3,044,269 Patented July 17, 1962 ice plate wall members areeach formed by a press to assume the shape in transverse section of aportion of a corrugation. Each steel plate wall member is welded at itsends to the respective upper and lower box beam 19, 21, and at its sidesto adjacent wall members. Thus, the steel plate wall members form acontinuous corrugated web which extends between the upper and lower boxbeams. .This web together with the upper and lower box beams make up theouter wall of the hull 11. As can be seen from the drawings, thecorrugations formed by the steel plate wall members 23 have amplitudesuch that they extend over most of the width of the box beams 19, 21. Ascan be seen from FIGS. 1 and 2, the box beams 19, 21 extend all aroundthe outer periphery of the hull 11, and the corrugations likewise,except between the right and left rear spud wells 15, 17 where thecorrugations are replaced by a wall section 25 which has the samestructure as the decking, to be hereinafter described. The upper andlower box beams 19, 21 in the embodiment herein shown and described haverectangular cross-section, though it is apparent that they could takeother cross-section forms, as for example, triangular. The box beams atthe spud Wells 13, 15, 17 are twice as wide as elsewhere, and areprovided with a vertical partition 27 (see FIG. 10). The hull side wallconstruction employing upper and lower box beams and the corrugated webas just described, is quite simple, yet is very strong and rigid. Thehull bottom is made up of corrugated steel plate members 29 formed likethose of the side wall structure. These bottom plates are welded to eachother to form the hull bottom, with the valleys of the corrugationsrunning parallel to the center line of the hull 11 which passes midwaybetween the rear spud wells 15, 17. The outer edges of the bottom arewelded to the inner side face of the side wall lower box beam 21 (seeFIG. 6). The upper or main deck is made up of beams 31 formed fromstrips of steel plate material. The transverse cross-section of thesedecking beams may be seen in FIG. 6, and includes a surface portion, adownwardly extending short flange on one side of the surface portion,and a generally block J shaped flange depending from the other side ofthe surface portion. The decking beams are joined at their longitudinaledges by welding, with the outer surface of the short flange of one beambearing against the outer surface of the upper portion of the J shapedflange of the adjacent decking beam, with the surface portions of thedecking beams lying generally in a common plane. Short stifiener Lshaped beams (not shown) extend transversely between adjacent deckingbeams at spaced intervals and are welded thereto. The decking beams 31extend in the direction parallel to the hull center line which passesmidway between the rear spud wells 15, 17. The decking'is supported bycross beams 33, which extend transversely of the decking beams at spacedintervals and are welded at their ends to the inner face of the sidewall upper'box beam 19. The cross beams are supported at spacedintervals by vertical columns 35 which have their footing on thecorrugated bottom 29 (see FIGS. 6 and 7). The lower or inner deck of thehull is made up of decking beams 37 which are like the decking beams 31of the upper deck hereinbefore described. The beams of the lower deckare supported by a plurality of transverse bulkheads 39 which are shapedto conform with the hull bottom corrugations and are welded to the hullbottom members 29. An L shaped stiffener member 41 is fixed by weldingto each bulkhead 39, running parallel to bulkheads 39 and trans verselyof the decking members 37. A pair of rectangular deck sections 43 extendoutwardly from the rear side of center line, to form a slot over which adrilling derrick afiter more fully described.

(not shown) can be erected. The deck extensions 43 are held in place bysuitable bracing members 45.

Each of the three spud wells 13, 15, 17, is centered on a line bisectingthe angle between respective adjacent hull side walls Each spud well maybe considered as having an outer wall portion 47 and an inner wallportion 49. The outer wall portion is generally polygonal in shape, inplan, each side of the polygon being made up ofa length of upper andlower box beam 19, 21 and corrugated web 23 forming a segment of thehull side wall structure as hereinbefore described. The inner wall 49 ofeach spud 'welliis arcuate in shape, in plan, and is made up of curvedsteel plate members welded together. blies 51, as well "as rackguidestructures 53, to be herein- Each spud well is of course designedtoreceive a spud tower 55. The spud towers are of triangular transversecross-section and each comprises three spud tower columns 57 at thetriangle vertices and which are held in rigid spaced parallel relationby tubular latticed trusswork members. A-t spaced intervals along thespud column length there is a tubular truss member 59 disposed betweeneach pair of adjacent spud columns and lying in a horizontal plane.Additional sets'of truss members 61 extend irom near the midpoint ofeach horizontal truss member 59 at alternate tower levels both upwardand downward, to adjacent tower columns. other set of truss members 63extends vertically from midpoint to midpoint of the horizontal trussmembers 59. Still another set of truss members 60 extends horizontallyat each levelof horizontal truss members and from midpoint to midpointof same. Each (tower column 57 is made up of a primary member 65, a rack69, and rack.

support members 67. The primary member 65 is in the form of a heavysteel slab of rectangular cross-section havinga width several times itsthickness (see FIG. 11). The primary member may be considered as havinga front face 71 and a rear face 73. The rack 69 is disposed in suchmanner that a plane bisecting the rack and rack face will beperpendicular to the faces of the primary member 65 and will bisect theprimary member longitudinally. The rack 69 is held in rigid spacedrelation to said primary member by a pair of rack support members 67.The rack support members are heavy steel plate strips welded along onelongitudinal edge to the rear face 73 of the primary member 65 and alongthe other longitudinal edge to a respective side face of the rack 69.In.

transverse cross-section, the rack supportmernbers, 67 form the sides,and. the primary members 65 the base, of an isosceles triangle, withsaid primary member. extending symmetrically beyond the triangle base oneach side thereof. The portions 75 of the primary member which extendbeyond the triangle base just mentioned, are utilized as guide surfacesas will be hereinafter more fully explain'ed.

Each spud tower carries a watertight cylindrical pontoon tank 77 at itslower end. Each pontoon tank is provided with sea cocks (not shown) forflooding and draining purposes. Each spud tank is also provided withjetting means (not shown) for the conventional well.

known purpose. Each spud tank is made up of a center column '79, trusswork bracing members 81, wall sections 83, a top 85, a bottom 87, and areinforcing web 89 (see FIG. The center column 79 is a large tubularmember centered on the tank longitudinal axis. The bracing members 81are tubular and may be considered in sets. One set radiates from thecenter column 79 to the front face 71 of each tower column 57. Anotherset forms horizontal triangles at a plurality of tower levels, with thetower columns 57 as vertices. wall sections 83, made up of curved steelplate sheets joined by welding and extending between adiacent towercolumns 57, with each side edge of each wall section 83 being welded tothe front face 71 of a tower column primary member 65.

There are three tank The wall section is in each caseformed suitably toaccommodate the tower column guide structure (see FIG. 4). The spud tanktop 85 is a convex dish of heavy steel plate material welded to the tankside walls 83. The tank bottom 87 is a concave dish of heavy steel platematerial welded to the tank side Walls 83. The bottom reinforcing web 89is a convex dish of heavy steel plate material with a circular section sremoved from its center portion so that the web extends from the insideof the tank bottom upwardly at an angle and joinsthe tank side walls.The web is welded both to 1 the tank bottom 87 and to the tank sidewalls 83.

Each spud well carries three rack drive as'semand small wall sections91, 93, 95 respectively. Each of these wall sections has rectangularshape, .The wall sections are held in rigid spaced relation bytransverse heavy steel plate partitions 97. The gear case carries threevertically aligned large shaft support openings, and three verticallyaligned intermediate shaft support openings.

The large and intermediate shaft support openings for each drive unitare horizontally aligned. The large and intermediate gear case wallscarry top, intermediate, and

lower rectangular slots at their left side portions, and the enn're leftside of the gear case between the large and intermediate walls is closedby welded steel plate mem-- bers 99. The drive units may be designatedas upper, intermediate, and lower. Each drive unit comprises a primarygear box 101 which is a prepackaged self-contained unit, driven by anelectric motor 103, and having an output pinion 105. The primary gearbox of each drive unit fits into a respective slot of the gear case andis welded thereto. An intermediate gear shaft 107 is journaled in eachintermediate shaft support opening, and

r carries a bull gear 109 at one end and an output pinion 111 at theother end. The output pinion 105 of the primary gear box 103 engages thebull gear 109 of the intermediate shaft 107. A large gear shaft 113 isjournaled to each large shaft support opening, and carries a bull gear115 and an output pinion 117. The output pinion 111 of the intermediateshaft 107 engages the bull gear 115 of the large shaft 113, and theoutput pinion 117 of the large shaft 115 is adapted for engaging therespective rack 69.

There are three gear case assemblies 51 disposed in each spud well. Eachgear case is incorporated into the spud well structure in uprightposition between the upper and lower side wall box beams 19, 21. Theheight of the gear case is made equal to the distance between the upperand lower box beams, and the top and bottom edges of the gear case areWelded to the respective box beam (see FIG. 10). The gear cases arespaced 120 degrees apart, and so that a respective vertical planepassing through the spud well center is parallel to the gear case sidewalls and bisects the gear case output pinions. 117, with said planealso bisecting the angle between adjacent hull sides in the case of theoutboard drive assembly of each spud well. The manner in which the sidewalls of a particular gear case are joined to the hull structure isshown by FIG. 9 for the case of an inboard gear box. The right edge ofthe gear box large wall 91 is welded to a side edge of the spud wellarcuate wall section 49. A strip 119 of heavy steel plate extends fromthe right edge of the gear box small wall at an angle to the right endportion of the gear box large wall 91 and is welded thereto. The leftedge of the gear box small wall 95 is joined by a heavy steel platestrip 121 to the end of the corrugated web 23 of the spud well wall. Theends of the corrugated Webs of the spud well wall and the hull side wallare joined by a section of heavy steel plate wall. A section of wall 125made up of decking, separates the gear box from the hull interior, andis provided with an access opening (not shown).

As hereinbefore mentioned, each spud well is provided with tower columnguide structures 53 at each drive assembly location (see FIGS. 4 andThere are two vertically aligned tower column guide structures 53 ateach drive assembly location. Each guide structure is made up of a pairof parallel spaced guide rails 125 which are generally U shaped in crosssection. Each guide rail is held rigid by a support structure composedof heavy steel plate sections. Each guide rail support structure is madeup of two trapezoidal side sections 127, a triangular top section 129and a triangular bottom section. The short parallel side of eachtrapezoidal section is welded to the respective box beam 19, 21 whilethe long parallel side is welded to the respective guide rail 125. Thetrapezoidal sides diverge from the guide rail to the respective boxbeam. The open ends of the enclosure formed by the trapezoidal sidewalls, the respective box beam and the respective guide rail are closedby top and bottom triangular sections 129.

The manner of operation and the electrical system of the mobile seaplatform herein described is essentially the same as that of theplatform disclosed by my copending application S.N. 473,885aforementioned. The electric drive motors are each equipped withelectromagnetic brakes which automatically engage when the motor isde-energized. A heliport 131 is mounted on top of the front spud tower.

While I have shown my invention in only one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof.

I claim:

1. In combination, a spud well, and a spud in said spud well, said spudcomprising a tower structure including a plurality of vertical towercolumns forming corners for said structure and a plurality of membersforming an open lattice network holding said columns in rigid spacedrelationship; each said tower column comprising a vertically disposedflat steel slab of horizontal width several times its thickness, themembers of said lattice network being secured to one major vertical faceof each said slab inwardly of the vertical edges of said face; avertical rack bar disposed outwardly of the opposite major face of eachslab in a vertical plane bisecting said slab, and vertically disposedhorizontally diverging rack support strips connecting opposite sidefaces of said rack bar to said opposite major face of said slab alongvertical lines spaced inwardly from the vertical edges of said face;whereby the vertical longitudinal edges of said slab form extended guideformations free of interference from said lattice network members andsaid rack supporting strips; and supporting and guiding elements on saidspud well in cooperating engagement with said formations.

2. The combination in accordance with claim '1, in which the major planeof each slab is perpendicular to the vertical plane bisecting thecorresponding corner angle of said structure.

3. The combination in accordance with claim 1, in which the centralvertical plane of each rack bar is coplanar with the vertical planebisecting the corresponding corner angle of said structure.

4. In combination, a spud well, and a spud in said spud Well, said spudcomprising a tower structure including a plurality of vertical towercolumns forming corners for said structure and a plurality of membersforming an open lattice network holding said columns in rigid spacedrelationship; one of said tower columns comprising a vertically disposedflat steel slab of horizontal width several times its thickness, themembers of said lattice network being secured to one major vertical faceof said slab inwardly of the vertical edges of said face; a verticalrack bar disposed outwardly of the opposite major face of said slab in avertical plane bisecting said slab, and vertically disposed horizontallydiverging rack support strips connecting opposite side faces of saidrack bar to said opposite major face of said slab along vertical linesspaced inwardly from the vertical edges of said face; whereby thevertical longitudinal edges of said slabform extended guide formationsfree of interference from said lattice network members and said racksupporting strips; and supporting and guiding elements on said spud Wellin cooperating engagement with saidformations.

5. In combination with a first structural support, a col umn for guidedand power-driven lengthwise motion relative to said support, said columncomprising: a single elongate flat slab forming the primary member ofsaid column and having a width several times its thickness, a rack barspaced from one major face of said slab and lying parallel to the lengthof said slab in the lengthwise bisecting plane thereof, and a pair ofelongate flat strips. having one lengthwise edge of each welded to arespective lateral face of said rack bar and diverging angularlytherefrom with the other lengthwise edge of each said strip welded tosaid major face of said slab along respective lines adjacent-andparallel to, but spaced inwardly from the corresponding lengthwise slabedges forming slab-edge guiding formations extending beyond theconnections of said strips to said slabs; a second structural supportconnected to said slab at the other major face of said slab; and meanson said first structural support for engaging and receiving said guiding.formations to restrict them to such lengthwise direction of motion.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Popular Science, January 1956, p. 160. EngineeringNews-Record, Apr. 5, 1956, p. 26.

